Assembly process for tensioning elements and related systems

Abstract

A method of manufacturing a surgical instrument mountable to a remotely controllable manipulator configured to operate the surgical instrument includes applying a first tension to a first tensioning element, applying a second tension to a second tensioning element, and maintaining the first and second tensions in the first and second tensioning elements while a first rotatable cylinder is locked to a second rotatable cylinder. The first tensioning element and the second tensioning element are each coupled to a distal end component of the surgical instrument and are coupled to one another such that a tension in one of the first tensioning element and the second tensioning element is transmitted at least in part to the other of the first tensioning element and the second tensioning element.

What is claimed is: 
     
       1. A method of manufacturing a surgical instrument mountable to a remotely controllable manipulator configured to operate the surgical instrument, the method comprising:
 applying a first tension to a first tensioning element coupled to a first rotatable cylinder of the surgical instrument by using a first motor to apply a first torque to the first rotatable cylinder; 
 applying a second tension to a second tensioning element coupled to a second rotatable cylinder of the surgical instrument by using a second motor to apply a second torque to the second rotatable cylinder; and 
 maintaining the first and second tensions in the first and second tensioning elements while the first rotatable cylinder is being locked to the second rotatable cylinder; 
 wherein the first tensioning element and the second tensioning element are each coupled to a distal end component of the surgical instrument and are coupled to one another such that a tension in one of the first tensioning element and the second tensioning element is transmitted at least in part to the other of the first tensioning element and the second tensioning element. 
 
     
     
       2. The method of  claim 1 , wherein applying the first tension and the second tension comprises applying the first tension and the second tension based on an operator input indicative of target tensions. 
     
     
       3. The method of  claim 1 , further comprising removing a first constructional stretch from the first tensioning element and a second constructional stretch from the second tensioning element before applying the first and second tensions to the first and second tensioning elements. 
     
     
       4. The method of  claim 3 , further comprising relaxing the first and second tensioning elements after removing the first constructional stretch and the second constructional stretch and before applying the first and second tensions to the first and second tensioning elements. 
     
     
       5. The method of  claim 3 , wherein removing the first constructional stretch and the second constructional stretch comprises cyclically applying a tension to each of the first and second tensioning elements. 
     
     
       6. The method of  claim 1 , wherein the first rotatable cylinder is manually lockable to the second rotatable cylinder, and the method further comprises providing an operator feedback while an operator is manually locking the first and second rotatable cylinders together. 
     
     
       7. The method of  claim 6 , further comprising:
 measuring positions of the first and second rotatable cylinders to monitor a loop length; and 
 providing the operator feedback to maintain the loop length. 
 
     
     
       8. The method of  claim 7 , wherein measuring the positions of the first and second rotatable cylinders comprises measuring positions of the first and second motors based on a plurality of signals from a plurality of encoders coupled to the first and second motors. 
     
     
       9. The method of  claim 1 , further comprising locking the first and second rotatable cylinders by translating the second rotatable cylinder toward the first rotatable cylinder. 
     
     
       10. The method of  claim 1 , wherein:
 applying the first tension to the first tensioning element comprises applying the first tension to the first tensioning element based on a friction force on the first tensioning element, and 
 applying the second tension to the second tensioning element comprises applying the second tension to the second tensioning element based on a friction force on the second tensioning element. 
 
     
     
       11. The method of  claim 1 , wherein the first tension and the second tension are applied while a position of an instrument joint coupled to the first and second tensioning elements is maintained. 
     
     
       12. The method of  claim 1 , further comprising:
 applying a third tension to the first tensioning element while the first and second rotatable cylinders are engaged such that a tension in the second tensioning element is substantially zero, 
 applying a fourth tension to the second tensioning element while the first and second rotatable cylinders are engaged such that a tension in the first tensioning element is substantially zero, and then 
 estimating a difference between an amount of rotation when the third tension is applied and an amount of rotation when the fourth tension is applied, 
 wherein the first tension and the second tension are applied to the first tensioning element and the second tensioning element, respectively, when the difference exceeded a predefined threshold. 
 
     
     
       13. The method of  claim 1 , wherein the first tension and the second tension are applied while the first rotatable cylinder and the second rotatable cylinder are disengaged from one another, and the method further comprises engaging the first rotatable cylinder to the second rotatable cylinder. 
     
     
       14. A method of manufacturing a surgical instrument mountable to a remotely controllable manipulator configured to operate the surgical instrument, the method comprising:
 applying a tension to a first tensioning element coupled to a first rotatable cylinder of the surgical instrument by using a first motor to rotate the first rotatable cylinder relative to a second rotatable cylinder of the surgical instrument; and 
 maintaining the tension in the first tensioning element and maintaining the tension in a second tensioning element coupled to the second rotatable cylinder while the first rotatable cylinder is being locked to the second rotatable cylinder; 
 wherein the first tensioning element and the second tensioning element are coupled to a distal end component of the surgical instrument and are configured such that a tension in one of the first tensioning element and the second tensioning element is transmitted at least in part to the other of the first tensioning element and the second tensioning element. 
 
     
     
       15. The method of  claim 14 , wherein applying the tension comprises applying the tension based on an operator input indicative of a target tension. 
     
     
       16. The method of  claim 14 , further comprising removing a first constructional stretch from the first tensioning element and removing a second constructional stretch from the second tensioning element before applying the tension. 
     
     
       17. The method of  claim 16 , further comprising relaxing the first and second tensioning elements after removing the first constructional stretch and the second constructional stretch and before applying the tension. 
     
     
       18. The method of  claim 16 , wherein removing the first construction stretch and the second constructional stretch comprises cyclically applying a tension to each of the first and second tensioning elements. 
     
     
       19. The method of  claim 14 , wherein the first rotatable cylinder is manually lockable to the second rotatable cylinder, and the method further comprises providing an operator feedback while an operator is manually locking the first and second rotatable cylinders together. 
     
     
       20. The method of  claim 19 , further comprising:
 measuring positions of the first and second rotatable cylinders to monitor a loop length; and 
 providing the operator feedback to maintain the loop length. 
 
     
     
       21. The method of  claim 14 , further comprising locking the first and second rotatable cylinders by translating the second rotatable cylinder toward the first rotatable cylinder. 
     
     
       22. The method of  claim 14 , wherein:
 applying the tension to the first tensioning element comprises applying the tension to the first tensioning element based on a friction force on the first tensioning element.